• International Journal of Aeronautical and Space Sciences
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• v.11 no.1
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• pp.31-40
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• 2010

For weapon cueing and Head-Mounted Display (HMD), it is essential to continuously estimate the motion of the helmet. The problem of estimating and predicting the position and orientation of the helmet is approached by fusing measurements from inertial sensors and stereo vision system. The sensor fusion approach in this paper is based on nonlinear filtering, especially expended Kalman filter(EKF). To reduce the computation time and improve the performance in vision processing, we separate the structure estimation and motion estimation. The structure estimation tracks the features which are the part of helmet model structure in the scene and the motion estimation filter estimates the position and orientation of the helmet. This algorithm is tested with using synthetic and real data. And the results show that the result of sensor fusion is successful.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.1964-1981
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• 2014

An improved Mean-Shift (MS) tracker called joint CB-LBWH, which uses a combined weighted-histogram scheme of CBWH (Corrected Background-Weighted Histogram) and LBWH (likelihood-based Background-Weighted Histogram), is presented. Joint CB-LBWH is based on the notion that target representation employs both feature saliency and confidence to form a compound weighted histogram criterion. As the more prominent and confident features mean more significant for tracking the target, the tuned histogram by joint CB-LBWH can reduce the interference of background in target localization effectively. Comparative experimental results show that the proposed joint CB-LBWH scheme can significantly improve the efficiency and robustness of MS tracker when heavy occlusions and complex scenes exist.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.9
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• pp.4355-4374
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• 2018

Crowd escape event detection has become one of the hottest problems in intelligent surveillance filed. When the 'escape event' occurs, pedestrians will escape in a disordered way with different velocities and directions. Based on these characteristics, this paper proposes a Direction-Collectiveness Model to detect escape event in crowd scenes. First, we extract a set of trajectories from video sequences by using generalized Kanade-Lucas-Tomasi key point tracker (gKLT). Second, a Direction-Collectiveness Model is built based on the randomness of velocity and orientation calculated from the trajectories to express the movement of the crowd. This model can describe the movement of the crowd adequately. To obtain a generalized crowd escape event detector, we adopt an adaptive threshold according to the Direction-Collectiveness index. Experiments conducted on two widely used datasets demonstrate that the proposed model can detect the escape events more effectively from dense crowd.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1034-1036
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• 2006

In this paper, I used microprocessor and sensor and designed to improve the efficiency of the photovoltaic system the photovoltaic position tracker device, and compared the normal photovoltaic system of fixed form with the photovoltaic system of solar position tracked form. Moreover, compared the catalogue of solar cell module and the simulation through a mathematics modelling with the solar cell's characteristic interpreting and, composed an power conversion system with boost converter and voltage source inverter. Used the constant voltage control method for maximum power point tracking in boost converter control and, used the SPWM(Sinusoidal Pulse Width Modulation) control method in inverter control.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.175-178
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• 2016

안드로이드 스마트폰의 성능을 향상시키기 위해서는 스마트폰 및 앱의 특성을 추출하는 것이 중요하다. 본 논문은 효율적인 메모리 관리를 위한 전단계로써 메모리 부족 및 부팅 특성을 모니터링 하는 AppMemTracker 앱을 제작하였다. 이 앱에 구현된 백그라운드 서비스들이 메모리 부족 및 부팅 특성에 관련된 정보를 추출하여 주기적으로 우리의 메일에 전송한다. AppMemTracker가 정확하게 동작하는지를 확인하기 위해 여러 스마트폰과 안드로이드 버전에서 실험 하였고, 정확한 정보가 추출되는 것을 확인하였다.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1251-1253
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• 2000

This paper describes control of water pumping system using PV array. An integral part of the system with various system components be constructed PV array. maximum power point tracker BLDC motor and pump. BLDC motor has the quality of torque output and efficiency, has been more widely used in a field for multifarious application. However pumping system using PV array has limited for application because output characteristics of solar cell are greatly fluctuate on the variations of insolation, temperature and loads. For this reson, in this paper each parts efficiently contoroled by the maximum power point tracker, the vector control method of BLDC motor and the pressure PI controller using TMS320C- 31.

• ETRI Journal
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• v.37 no.3
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• pp.617-625
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• 2015

In this paper, a steering control system for the path tracking of autonomous vehicles is described. The steering control system consists of a path tracker and primitive driver. The path tracker generates the desired steering angle by using the look-ahead distance, vehicle heading, and a lateral offset. A method for applying an autonomous vehicle to path tracking is an advanced pure pursuit method that can reduce cutting corners, which is a weakness of the pure pursuit method. The steering controller controls the steering actuator to follow the desired steering angle. A servo motor is installed to control the steering handle, and it can transmit the steering force using a belt and pulley. We designed a steering controller that is applied to a proportional integral differential controller. However, because of a dead band, the path tracking performance and stability of autonomous vehicles are reduced. To overcome the dead band, a dead band compensator was developed. As a result of the compensator, the path tracking performance and stability are improved.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.1059-1062
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• 2000

Infrared (IR) seeker identifies the location of a target by detecting the infrared energy radiated from the target, and enables the missile to track the target. To improve the tracking performance, a counter- countermeasure (CCM) is essential to minimize the effect of the countermeasure (CM), which is operated by a target to protect itself. In this paper, we propose a crossed array tracker (CAT) using two-color CCM algorithm. The CAT using the proposed algorithm shows better tracking performance by minimizing the effect of CM.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2594-2596
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• 2001

In this paper, a video tracker with a TMS320C31 DSP is designed and implemented. It is intended to work with PC through PCI Bus and can be used in real-time applications. The DSP board is capable of grabbing image data from camera, and calculating the position of a target, and trackig its movement. The tracking situation can be displayed in a monitor and displacement of the movement is fed back to pan and tilt the camera. Experimental results show that the tracker implemented here works well in real applications.

• Proceedings of the KAIS Fall Conference
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• 2004.11a
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• pp.234-239
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• 2004

This paper describes preliminary results we have obtained in developing a computer vision system based on active IR illumination for real time gaze tracking for interactive graphic display. Unlike most of the existing gaze tracking techniques, which often require assuming a static head to work well and require a cumbersome calibration process fur each person, our gaze tracker can perform robust and accurate gaze estimation without calibration and under rather significant head movement. This is made possible by a new gaze calibration procedure that identifies the mapping from pupil parameters to screen coordinates using the Generalized Regression Neural Networks (GRNN). With GRNN, the mapping does not have to be an analytical function and head movement is explicitly accounted for by the gaze mapping function. Furthermore, the mapping function can generalize to other individuals not used in the training. The effectiveness of our gaze tracker is demonstrated by preliminary experiments that involve gaze-contingent interactive graphic display.